氢氧化镁在阻燃PVC薄膜中的应用

Application of Magnesium Hydroxide in Flame Retardant PVC Film

通过机械法制备超细氢氧化镁(MH),并利用硅烷偶联剂(R-903)对其进行活化,添加到聚氯乙烯(PVC)阻燃薄膜中替代部分氢氧化铝(ATH)和三氧化二锑(ATO),利用热失重仪、极限氧指数测试仪、自动白度仪等对该阻燃薄膜的热性能、燃烧性能、薄膜白度等进行研究。结果表明,超细活化MH不仅可以提高PVC阻燃薄膜的热稳定性,显著提高其抑烟性能,并且能够有效降低成本。与市售ATH粉体和机械法制备得到的超细MH相比,超细活化MH在粒径、比表面积、热稳定性方面均有明显的优势,添加进PVC阻燃薄膜中,可以发现,随着MH替代ATH和ATO量的增加,薄膜的极限氧指数和抑烟效果均相应提升;特别地,当用质量分数为4.3%的超细活化MH替代相同量的ATH和ATO后,能够在保持薄膜极限氧指数以及烟密度等性能的同时,提升薄膜的热稳定性和成炭的致密性,表明该超细活化MH具备可替代部分ATH的潜力。随着所制备的超细活化MH的加入,阻燃薄膜的白度能够得到有效保证。

Ultrafine magnesium hydroxide(MH)was prepared via physical grinding,which was modified by the silane coupling agent(R-903).For the purpose of replacing part component of aluminum hydroxide(ATH)and antimony trioxide(ATO),it was further added into the flame retardant film of polyvinyl chloride(PVC).Several properties such as the thermal properties,combustion properties and whiteness of the flame retardant film were studied by thermogravimetry,limiting oxygen index and automatic whiteness instrument.The results showed that the thermal stability can be enhanced,the smoke suppression performance can be improved significantly,and the cost can be also reduced.Specifically,compared with the commercial ATH,the prepared ultrafine activated MH displays the obvious advantages in particle size,specific surface area and thermal stability.When the modified MH is added into the flame retardant film,it can be found that both the oxygen index and smoke suppression effect of film are increased with the enhanced replacing weight of ATH.Especially,the thermal stability and carbon forming compactness of the film can be improved while 8 parts of ATH and ATO are replaced by the same fraction of ultrafine activated MH powder,and the oxygen index and smoke density of the film can be maintained under this situation,which indicated that the ultrafine activated MH has the potential of replacing part of ATH.In the end,with the addition and substitution of the prepared ultrafine activated MH,the whiteness of the flame retardant film can be effectively guaranteed.